The present invention relates to devices and methods for treating urinary incontinence, such as urinary incontinence in women resulting from intrinsic sphincter deficiency.
Urinary incontinence is a widespread problem throughout the world. Urinary incontinence affects people of all ages and can severely impact a patient both physiologically and psychologically.
One form of urinary incontinence suffered by women is intrinsic sphincter deficiency (ISD), a condition in which the valve of the urethral sphincter does not function properly, thus preventing proper coaptation of the urethra. Without proper coaptation, a person is unable to control urinary leakage. ISD can arise from loss of urethral vasculature, thinning of urethral mucosa, loss of the urethral connective tissue elements, neurologic compromise of the sympathetic smooth muscle, or compromise of the external striated sphincter.
Another form of urinary incontinence is known as bladder neck hypermobility. Bladder neck hypermobility can arise from loss of support by the pelvic floor and loss of suspension by the pelvic connective tissue in ligaments and fascia. In this condition, the bladder neck and proximal urethra descend in response to increases in intra-abdominal pressure, resulting in uncontrollable urinary leakage.
Common approaches to treating urinary incontinence in women require invasive surgical procedures either through the vaginal wall or the abdominal wall. These surgical procedures focus on elevating the urethrovesical junction by introducing a sling that passes to the posterior side of the urethra and suspending the urethra from an anatomical structure located anterior to the urethra, for example, the abdominal fascia, the pubic bone, or the Cooper""s ligament. Surgical treatments of urinary incontinence that use slings typically involve placing the sling under the urethra to provide suburethral support. Slings of this type simultaneously compress and suspend the urethra to treat urinary incontinence. One disadvantage of these procedures is the invasive nature of these procedures. Another disadvantage is that weight gain or loss can affect the suspension of the urethra causing it to become too tight or too loose. Still another disadvantage is that some types of slings may shrink with age and may cause difficulties with voiding. Other invasive surgical approaches to treating urinary incontinence include the use of vaginal wall slings and/or artificial urinary sphincters.
Periurethral injection (PI) of biocompatible bulk-enhancing agents, another approach to treating urinary incontinence, has the advantage of being a less invasive form of treatment and, thus, can be performed on an outpatient basis. PI uses bulk-enhancing agents, such as Teflon(copyright) (DuPont), autologous fat, and collagen, to increase pressure on the urethra and reduce the size of the urethral lumen, providing additional resistance to the flow of urine. Such injections may be accomplished either transurethrally or periurethrally. Typically, however, repeat treatments of PI are required because the bulk-enhancing agent can be absorbed by the body or translocated from the site of injection. Another drawback to PI is that accidental over-bulking may result in undesirable urinary retention requiring catheterization to void until the injectant is absorbed by the body.
The present invention relates to a treatment for urinary incontinence without drawbacks associated with more invasive surgeries or PI. The invention generally involves coapting a urethra externally between a sling and a vaginal wall. The term xe2x80x9curethra,xe2x80x9d as used herein, generally includes the bladder neck. Because of the minimally invasive nature of the invention, a procedure according to the invention can be performed in conjunction with other transvaginal procedures. In addition, such a procedure can quickly and easily be reversed as the sling may be held in place by removable securing devices such as sutures or surgical staples.
In one aspect, the invention features a surgical device for treating urinary incontinence that includes a curved needle, a dilator, and a sling. A distal end of the dilator is coupled to a proximal end of the curved needle, and a distal end of the sling is coupled to a proximal end of the dilator.
In some embodiments, the curved needle includes a curvature sufficient to allow the needle to enter the body from the vaginal cavity and through the vaginal wall, pass to one side of the urethra, continue over an anterior side of the urethra, and exit the body on the other side of the urethra.
The dilator generally can be any shape in which the distal end is tapered and the proximal end can create an opening to accommodate a sling as it follows the dilator into the body. In some embodiments, the dilator can be substantially flat and triangular in shape. In other embodiments, the dilator can be substantially rectangular and tapered at the distal end. The dilator can be made from one or more biocompatible materials such as a plastic or metal. The dilator can also include markings to indicate the location of the sling within the body.
The sling can be made of one or more biocompatible materials selected from the group consisting of a natural material, a synthetic material, or a combination of a natural material and a synthetic material. The sling can be about 0.5 cm to about 4 cm in width. In a particular embodiment, the sling is about 1 to about 3 cm in width. In another particular embodiment, the sling is about 1.5 to about 2.5 cm in width.
In some embodiments, a tether couples the curved needle to the dilator. Examples of the form the tether may take includes a wire, a suture, and a portion of the sling.
In some embodiments, a first portion of the sling can be smaller in width than a middle portion of the sling. In a particular embodiment, the first portion of the sling can couple the sling to the dilator. In another particular embodiment, the first portion of the sling can couple the dilator to the needle.
In some embodiments, a pouch can be fixedly attached to the dilator and releasably attached to the sling. In other embodiments, the surgical device can include a stiffener to maintain the sling in a generally planar orientation as it enters the body.
In another aspect, the invention features a surgical device that includes a sling, a first tether with a proximal end coupled to a distal end of the sling, a second tether with a distal end coupled to a proximal end of the sling, a curved needle coupled to a distal end of the first tether, and a dilator disposed along the first tether between the curved needle and the distal end of the sling.
In yet another aspect, the invention features a method of treating urinary incontinence. The method includes introducing a sling into a body and positioning the sling on an anterior side of the urethra to coapt the urethra against the vaginal wall. The sling can be introduced into the body via the vaginal cavity and through the vaginal wall. In some embodiments, the sling is positioned to surround less than 360xc2x0 of the circumference of the urethra. In some embodiments, the sling is positioned to surround approximately 180xc2x0 of the circumference of the urethra on an anterior side of the urethra. In other embodiments, the sling is positioned to surround approximately 90xc2x0 to approximately 180xc2x0 of the urethra on the anterior side of the urethra.
In some embodiments, a surgical device according the invention is introduced into the body via the vaginal cavity and through the vaginal wall to pass to one side of the urethra, and then pass about the anterior side of the urethra, and to exit the body on the other side of the urethra into the vaginal cavity. The surgical device can include a curved needle, a dilator, and a sling, and the sling can be positioned in the body to coapt the urethra to an anterior portion of the vaginal wall in the body.
In some embodiments, the anterior of the urethra is separated from surrounding tissue, for example, the bladder. The separating step can be performed, for example, by using hydrodissection or balloon dissection.
In still another aspect, the invention features a method of treating urinary incontinence. The method includes introducing a surgical device into a body via the vaginal cavity. The surgical device can comprise a sling, including a distal end and a proximal end, and a first tether, including a distal end and a proximal end, wherein the proximal end of the tether is coupled to a distal end of the sling. The device can also include a second tether, including a distal end and a proximal end, wherein the distal end of the second tether is coupled to a proximal end of the sling. The device can also include a curved needle coupled to the distal end of the first tether and a dilator disposed along the first tether between the curved needle and the distal end of the sling. The curved needle is passed into the body via the vaginal cavity, through the vaginal wall to one side of the urethra, over an anterior portion of the urethra, and out of the body on the other side of the urethra into the vaginal cavity, creating a path for the first tether, the dilator, the sling, and the second tether to follow. The dilator is advanced along the path to position the sling about the urethra, leaving at least a portion of the second tether in the vaginal cavity. The dilator and at least a portion of the first tether exits the body into the vaginal cavity, leaving the sling in place about the anterior portion of the urethra to coapt the urethra to the anterior portion of the vaginal wall. The first tether and second tether are secured to an interior wall of the vaginal cavity.
The method can also include separating the anterior portion of the urethra from the surrounding tissue to create a pocket or opening to accommodate the sling.
These and other objects, along with advantages and features of the invention disclosed herein, will be made more apparent from the description, drawings, and claims that follow.